Pressure Control Solenoid "C" Control Circuit/Open
P0968 indicates the transmission control solenoid C has an open circuit or control problem, preventing proper pressure regulation in the transmission. This causes the transmission control module to lose precise control over fluid pressure, resulting in harsh shifts, slipping, or limp mode activation.
What You Might Notice
- Check Engine Light illuminated
- Transmission slips or hesitates during shifts
- Hard or abrupt gear shifting (banging into gear)
- Transmission overheating
- Increased fuel consumption
Most Common Causes
- 1
Solenoid C wiring open or disconnected
The electrical connector to solenoid C may be loose, corroded, or the wiring harness may have broken continuity. This is the most common cause and prevents voltage from reaching the solenoid.
- 2
Failed pressure control solenoid C
The solenoid coil may be internally open or burned out, causing it to not respond to PCM commands. This requires solenoid replacement.
- 3
Transmission control module circuit fault
A defective PCM output driver or circuit board issue prevents the transmission control module from sending proper voltage to solenoid C.
- 4
Low or contaminated transmission fluid
Dirty or low fluid level can cause solenoid response issues and poor circuit performance, though it rarely causes a complete open circuit.
How to Diagnose It
- 1
Check Solenoid C wiring open or disconnected — The electrical connector to solenoid C may be loose, corroded, or the wiring harness may have broken continuity. This is the most common cause and prevents voltage from reaching the solenoid.
- 2
Check Failed pressure control solenoid C — The solenoid coil may be internally open or burned out, causing it to not respond to PCM commands. This requires solenoid replacement.
- 3
Check Transmission control module circuit fault — A defective PCM output driver or circuit board issue prevents the transmission control module from sending proper voltage to solenoid C.
- 4
Check Low or contaminated transmission fluid — Dirty or low fluid level can cause solenoid response issues and poor circuit performance, though it rarely causes a complete open circuit.
How to Fix It
- 1
Inspect and repair solenoid wiring
Check the electrical connector and wiring harness to solenoid C for corrosion, loose connections, or broken wires. Clean corroded connectors with electrical cleaner and reseat connections firmly.
- 2
Replace pressure control solenoid C
If wiring is intact, the solenoid itself has failed internally. Remove the transmission pan (if accessible) or solenoid body and install a new pressure control solenoid C for your transmission.
- 3
Check transmission fluid condition
Inspect fluid level and condition; low or contaminated fluid can compound solenoid issues. Change transmission fluid and filter if dirty, burnt, or low.
- 4
Test and replace transmission control module
If solenoid and wiring are confirmed good, the PCM output circuit may be faulty. Have the transmission control module tested or replaced by a specialist.
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